mfd: ti_am335x_tscadc: Update logic in CTRL register for 5-wire TS

The logic in AFE_Pen_Ctrl bitmask in the CTRL register is different for five
wire versus four or eight wire touschscreens. This patch should fix this for
five-wire touch screens. There should be no change needed here for four and
eight wire tousch screens.

Signed-off-by: Jeff Lance <[e-mail]>
[bigeasy: keep the change mfd only]
Signed-off-by: Sebastian Andrzej Siewior <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/ti_am335x_tscadc.c

···
 	tscadc_writel(tscadc, REG_CLKDIV, tscadc->clk_div);
 
 	/* Set the control register bits */
-	ctrl = CNTRLREG_STEPCONFIGWRT |
-			CNTRLREG_STEPID;
-	if (tsc_wires > 0)
-		ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
+	ctrl = CNTRLREG_STEPCONFIGWRT |	CNTRLREG_STEPID;
 	tscadc_writel(tscadc, REG_CTRL, ctrl);
 
 	/* Set register bits for Idle Config Mode */
-	if (tsc_wires > 0)
+	if (tsc_wires > 0) {
+		tscadc->tsc_wires = tsc_wires;
+		if (tsc_wires == 5)
+			ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
+		else
+			ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
 		tscadc_idle_config(tscadc);
+	}
 
 	/* Enable the TSC module enable bit */
-	ctrl = tscadc_readl(tscadc, REG_CTRL);
 	ctrl |= CNTRLREG_TSCSSENB;
 	tscadc_writel(tscadc, REG_CTRL, ctrl);
 
···
 static int tscadc_resume(struct device *dev)
 {
 	struct ti_tscadc_dev	*tscadc_dev = dev_get_drvdata(dev);
-	unsigned int restore, ctrl;
+	u32 ctrl;
 
 	pm_runtime_get_sync(dev);
 
 	/* context restore */
 	ctrl = CNTRLREG_STEPCONFIGWRT |	CNTRLREG_STEPID;
-	if (tscadc_dev->tsc_cell != -1)
-		ctrl |= CNTRLREG_TSCENB | CNTRLREG_4WIRE;
 	tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
 
-	if (tscadc_dev->tsc_cell != -1)
+	if (tscadc_dev->tsc_cell != -1) {
+		if (tscadc_dev->tsc_wires == 5)
+			ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
+		else
+			ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
 		tscadc_idle_config(tscadc_dev);
-	restore = tscadc_readl(tscadc_dev, REG_CTRL);
-	tscadc_writel(tscadc_dev, REG_CTRL,
-			(restore | CNTRLREG_TSCSSENB));
+	}
+	ctrl |= CNTRLREG_TSCSSENB;
+	tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
 
 	tscadc_writel(tscadc_dev, REG_CLKDIV, tscadc_dev->clk_div);
 

include/linux/mfd/ti_am335x_tscadc.h

···
 	void __iomem *tscadc_base;
 	int irq;
 	int used_cells;	/* 1-2 */
+	int tsc_wires;
 	int tsc_cell;	/* -1 if not used */
 	int adc_cell;	/* -1 if not used */
 	struct mfd_cell cells[TSCADC_CELLS];